Blender Crash on .fbx export
Tips to avoid this: 


Activate Selected Objects (not whole scene) 
Activate only "Deform Bones" under Armature tab(so rig won't corrupt the FBX if many constraints, or loopback bones that might make it bug - will also export in a clean way, etc)
Disactivate "All Actions" from Animation tab (so that rig will export only it's aniamtion clips, not the whole scene animation
Make sure that SDS is at a reasonable level of Render Settings (1 or 2 max), SDS at 3 or 4 will take a long time to "Apply Modifiers" to the mesh - specially if it's a whole scene. You can optionally turn this "Apply Render setting modifiers" off under Geometries tab 


Then export and the software won't have to think so hard or ultimately crash.